The present invention relates to a knee prosthesis which is specifically designed to be used in revision surgery of previously performed knee arthroplasty. Revision surgery is performed to correct failures of previously implanted knee prosthesis. The knee prostheses fail for a number of reasons including malposition, loosening of the prosthesis, infection or dislocation. These categories are not necessarily mutually exclusive because infection, for example, may cause a loosening of the prosthesis which, in turn, might cause dislocation. When a prosthesis must be removed and a revision prosthesis inserted, it is often the case that additional bone must also be removed in order to stabilize the new prosthesis. When this occurs, the inferior portion of the femoral component of the prosthesis must be augmented to add additional thickness to compensate for the bone that has been removed. If the revision is done as a staged procedure, there is an opportunity to obtain a mold of the bone ends after the prosthesis has been removed. This allows an accurate revision prosthesis to be custom manufactured. A revision knee prosthesis could also be custom manufactured based on a construction determined through X-rays or other imaging systems.
However, it is preferable to perform the revision in a single surgical procedure. In this case, augmentation devices must be added to the femoral component during the surgical procedure. At the present time these augmentation devices are cemented into the inferior portion of the femoral component of the prosthesis. Care must be taken in accurately measuring the size of the augmentation devices because once they are cemented in position they are very difficult, if not impossible, to remove. The revision procedure is described in Surgery of the Knee, John M. Insall, Churchill Livingstone, N.Y. 1984, pp. 676-680.